source: trunk/kernel/syscalls/sys_read.c @ 610

Last change on this file since 610 was 610, checked in by alain, 3 years ago

Fix several bugs in VFS to support the following
ksh commandis : cp, mv, rm, mkdir, cd, pwd

File size: 9.5 KB
Line 
1/*
2 * sys_read.c - read bytes from a file
3 *
4 * Author     Alain Greiner (2016,2017,2018)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <kernel_config.h>
25#include <hal_kernel_types.h>
26#include <hal_uspace.h>
27#include <hal_irqmask.h>
28#include <hal_special.h>
29#include <errno.h>
30#include <vfs.h>
31#include <vmm.h>
32#include <thread.h>
33#include <printk.h>
34#include <process.h>
35
36
37extern uint32_t enter_sys_read;
38extern uint32_t enter_devfs_read;
39extern uint32_t enter_txt_read;
40extern uint32_t enter_chdev_cmd_read;
41extern uint32_t enter_chdev_server_read;
42extern uint32_t enter_tty_cmd_read;
43extern uint32_t enter_tty_isr_read;
44extern uint32_t exit_tty_isr_read;
45extern uint32_t exit_tty_cmd_read;
46extern uint32_t exit_chdev_server_read;
47extern uint32_t exit_chdev_cmd_read;
48extern uint32_t exit_txt_read;
49extern uint32_t exit_devfs_read;
50extern uint32_t exit_sys_read;
51
52
53/////////////////////////////////
54int sys_read( uint32_t   file_id,
55              void     * vaddr,
56              uint32_t   count )
57{
58    error_t       error;
59    vseg_t      * vseg;            // required for user space checking
60        xptr_t        file_xp;         // remote file extended pointer
61    vfs_file_t  * file_ptr;        // remote file local pointer
62    cxy_t         file_cxy;        // remote file cluster identifier
63    uint32_t      file_type;       // file type
64    uint32_t      file_offset;     // current file offset
65    uint32_t      file_attr;       // file_attribute
66    vfs_inode_t * inode_ptr;       // local pointer on associated inode
67    uint32_t      nbytes;          // number of bytes actually read
68    reg_t         save_sr;         // required to enable IRQs during syscall
69
70        thread_t    * this             = CURRENT_THREAD;
71        process_t   * process          = this->process;
72    xptr_t        process_owner_xp = process->owner_xp;
73 
74#if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
75uint64_t     tm_start = hal_get_cycles();
76#endif
77
78#if DEBUG_SYS_READ
79if( DEBUG_SYS_READ < tm_start )
80printk("\n[%s] thread[%x,%x] enter / vaddr %x / count %d / cycle %d\n",
81__FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start );
82#endif
83
84#if (DEBUG_SYS_READ & 1)
85enter_sys_read = (uint32_t)tm_start;
86#endif
87
88    // check file_id argument
89        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
90        {
91
92#if DEBUG_SYSCALLS_ERROR
93printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index %d\n",
94__FUNCTION__ , process->pid, this->trdid, file_id );
95#endif
96                this->errno = EBADFD;
97                return -1;
98        }
99
100    // check user buffer in user space
101    error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
102
103    if ( error )
104    {
105
106#if DEBUG_SYSCALLS_ERROR
107printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n",
108__FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
109vmm_display( process , false );
110#endif
111                this->errno = EINVAL;
112                return -1;
113    }
114
115    // get extended pointer on remote file descriptor
116    file_xp = process_fd_get_xptr( process , file_id );
117
118    if( file_xp == XPTR_NULL )
119    {
120
121#if DEBUG_SYSCALLS_ERROR
122printk("\n[ERROR] in %s : thread[%x,%x] undefined fd_id %d\n",
123__FUNCTION__, process->pid, this->trdid, file_id );
124#endif
125        this->errno = EBADFD;
126        return -1;
127    }
128
129    // get file descriptor cluster and local pointer
130    file_ptr = GET_PTR( file_xp );
131    file_cxy = GET_CXY( file_xp );
132
133    // get file type, offset, attributes and associated inode
134    file_type   = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );
135    file_offset = hal_remote_l32( XPTR( file_cxy , &file_ptr->offset ) );
136    inode_ptr   = hal_remote_lpt( XPTR( file_cxy , &file_ptr->inode ) );
137    file_attr   = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) );
138
139    // enable IRQs
140    hal_enable_irq( &save_sr );
141
142    // action depend on file type
143    if( file_type == INODE_TYPE_FILE )      // read from file mapper
144    {
145        // check file readable
146        if( (file_attr & FD_ATTR_READ_ENABLE) == 0 )
147            {
148
149#if DEBUG_SYSCALLS_ERROR
150printk("\n[ERROR] in %s : thread[%x,%x] file %d not readable\n",
151__FUNCTION__, process->pid, this->trdid, file_id );
152#endif
153            hal_restore_irq( save_sr );
154                    this->errno = EBADFD;
155                    return -1;
156            }
157
158        // move count bytes from mapper
159        nbytes = vfs_user_move( true,               // from mapper to buffer
160                                file_xp,
161                                vaddr, 
162                                count );
163        if( nbytes != count )
164        {
165
166#if DEBUG_SYSCALLS_ERROR
167printk("\n[ERROR] in %s : thread[%x,‰x] cannot read %d bytes from file %d\n",
168__FUNCTION__, process->pid, this->trdid, count, file_id );
169#endif
170            this->errno = EIO;
171            hal_restore_irq( save_sr );
172            return -1;
173        }
174    }
175    else if( file_type == INODE_TYPE_DEV )  // read from TXT device
176    {
177        // get cluster and pointers on TXT_RX chdev
178        xptr_t    chdev_xp  = chdev_from_file( file_xp );
179        cxy_t     chdev_cxy = GET_CXY( chdev_xp );
180        chdev_t * chdev_ptr = GET_PTR( chdev_xp );
181
182        volatile xptr_t    txt_owner_xp;   
183        uint32_t           iter = 0;
184
185        while( 1 )
186        {
187            // extended pointer on TXT owner process
188            txt_owner_xp  = hal_remote_l64( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) );
189
190            // check TXT_RX ownership
191            if ( process_owner_xp != txt_owner_xp )
192            {
193                if( (iter & 0xFFF) == 0 )
194                printk("\n[WARNING] in %s : thread[%x,%x] wait TXT_RX / cycle %d\n",
195                __FUNCTION__, process->pid, this->trdid, (uint32_t)hal_get_cycles() );
196
197                // deschedule without blocking
198                sched_yield( "wait TXT_RX ownership" );
199
200                iter++;
201            }
202            else
203            {
204                break;
205            }
206        }
207
208        // move count bytes from device
209        nbytes = devfs_user_move( true,             // from device to buffer
210                                  file_xp,
211                                  vaddr,
212                                  count );
213        if( nbytes != count )
214        {
215
216#if DEBUG_SYSCALLS_ERROR
217printk("\n[ERROR] in %s : thread[%x,‰x] cannot read data from file %d\n",
218__FUNCTION__, process->pid, this->trdid, file_id );
219#endif
220            this->errno = EIO;
221            hal_restore_irq( save_sr );
222            return -1;
223        }
224    }
225    else    // not FILE and not DEV
226    {
227
228#if DEBUG_SYSCALLS_ERROR
229printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n",
230__FUNCTION__, vfs_inode_type_str( file_type ) );
231#endif
232                this->errno = EBADFD;
233        hal_restore_irq( save_sr );
234                return -1;
235    }
236
237    // restore IRQs
238    hal_restore_irq( save_sr );
239
240    hal_fence();
241
242#if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
243uint64_t     tm_end = hal_get_cycles();
244#endif
245
246#if DEBUG_SYS_READ
247if( DEBUG_SYS_READ < tm_end )
248printk("\n[%s] thread[%x,%x] exit / cycle %d\n",
249__FUNCTION__ , process->pid, this->trdid, (uint32_t)tm_end );
250#endif
251
252#if CONFIG_INSTRUMENTATION_SYSCALLS
253hal_atomic_add( &syscalls_cumul_cost[SYS_READ] , tm_end - tm_start );
254hal_atomic_add( &syscalls_occurences[SYS_READ] , 1 );
255#endif
256
257#if (DEBUG_SYS_READ & 1)
258exit_sys_read = (uint32_t)tm_end;
259
260printk("\n***** timing to read one character *****\n"
261" - enter_sys_read          = %d / delta %d\n"
262" - enter_devfs_read        = %d / delta %d\n"
263" - enter_txt_read          = %d / delta %d\n"
264" - enter_chdev_cmd_read    = %d / delta %d\n"
265" - enter_chdev_server_read = %d / delta %d\n"
266" - enter_tty_cmd_read      = %d / delta %d\n"
267" - enter_tty_isr_read      = %d / delta %d\n"
268" - exit_tty_isr_read       = %d / delta %d\n"
269" - exit_tty_cmd_read       = %d / delta %d\n"
270" - exit_chdev_server_read  = %d / delta %d\n"
271" - exit_chdev_cmd_read     = %d / delta %d\n"
272" - exit_txt_read           = %d / delta %d\n"
273" - exit_devfs_read         = %d / delta %d\n"
274" - exit_sys_read           = %d / delta %d\n",
275enter_sys_read          , 0 ,
276enter_devfs_read        , enter_devfs_read        - enter_sys_read          ,
277enter_txt_read          , enter_txt_read          - enter_devfs_read        ,
278enter_chdev_cmd_read    , enter_chdev_cmd_read    - enter_txt_read          ,
279enter_chdev_server_read , enter_chdev_server_read - enter_chdev_cmd_read    ,
280enter_tty_cmd_read      , enter_tty_cmd_read      - enter_chdev_server_read ,
281enter_tty_isr_read      , enter_tty_isr_read      - enter_tty_cmd_read      ,
282exit_tty_isr_read       , exit_tty_isr_read       - enter_tty_isr_read      ,
283exit_tty_cmd_read       , exit_tty_cmd_read       - exit_tty_isr_read       ,
284exit_chdev_server_read  , exit_chdev_server_read  - exit_tty_cmd_read       ,
285exit_chdev_cmd_read     , exit_chdev_cmd_read     - exit_chdev_server_read  ,
286exit_txt_read           , exit_txt_read           - exit_chdev_cmd_read     ,
287exit_devfs_read         , exit_devfs_read         - exit_txt_read           ,
288exit_sys_read           , exit_sys_read           - exit_devfs_read         );
289#endif
290 
291        return nbytes;
292
293}  // end sys_read()
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